The wheelchair has continued to be an ever evolving mode of transportation for the elderly, injured and disabled. The wheelchair traces its roots back to the 5th century, where a Greek vase displays an image of a wheeled bed. In the late 16th century, King Phillip II of Spain was provided a chair with wheels in his later years. However, the introduction of what has come to be known as the “modern” wheelchair arguably evolved from the invention of the bicycle.
FIG. 1 is a perspective view of typical wheelchair assembly 100. In FIG. 1, an individual 150 is shown in a seated position in typical wheelchair assembly 100. Wheelchair assembly 100 generally includes frame 101, seat 102, backrest 103, armrest 104, first leg 105 and a second leg (not shown), front wheels 108 and 109 (not shown), and rear wheels 110 and 111. It should be appreciated that first leg 105 and the second leg (not shown) are structurally similar. The rear wheels 110 and 111 are attached to the rear of frame 101 of wheelchair assembly 100. The front wheels 108 and 109 are attached to the front of frame 101 of wheelchair assembly 100. Leg 105 further includes first member 112, second member 113 and third member 114. First and second members 112 and 113, respectively, are connected by bolt 115 and third member 114, which lies perpendicularly to second member 113, further connecting first member 112 with second member 113. Second member 113 is further secured to frame 101 of wheelchair assembly 100 by bolts 116 and 118, respectively. First leg 105 the and second leg (not shown) further include first and second footrests 119 and 120, respectively. The individual is shown sitting in seat 102, with back 151 placed against backrest 103 and right arm 152 placed on right armrest 104. The individual's legs 153 and 154 are bent at approximately a 90 degree angle, with right foot 155 placed on right footrest 119 and left foot 156 placed on left footrest 120 of wheelchair assembly 100.
Today, the “modern” wheelchair continues to be modified as a means for the development of rehabilitation and re-education programs for the injured, elderly and disabled. The need for modified rehabilitative wheelchairs stems from several problems faced by individuals bound to a wheelchair. A major concern for individuals who are permanently confined to a wheelchair is the potential for stiffened joints and tendons, as well as atrophy of the leg muscles. Furthermore, individuals who are temporarily confined to a wheelchair due to, for example, injury, stroke, arthritis, chronic pain, and knee or hip replacement surgery, must undergo exercise and therapeutic treatment to rehabilitate a person's unused or underused leg muscles. To alleviate this problem, those individuals confined permanently or temporarily to a wheelchair often undergo physical therapy. A typical rehabilitation patient undergoes one to two hours of rehab three days a week. However, rehab alone is insufficient and almost every patient needs to supplement their treatment on a daily basis with exercises performed outside of rehab.
Another problem faced by individuals bound to a wheelchair is the finite number of physical therapists and exercise machines present in a physical therapy or hospital facility. Even during the course of a physical therapy appointment, at any one time, a single physical therapist is assigned to a multitude of patients. As a result of the large ratio of patients to therapists, individuals who are wheelchair bound must periodically wait for personal one on one instruction by a physical therapist. Ideally, during these waiting periods, a patient will individually perform various exercises as prescribed by the therapist. However, similar to the limited number of physical therapists, a physical therapy facility or hospital also contains a limited number of exercise machines. As a result of the limited number of exercise machines compared to the number of patients at any given time, an individual often must wait until a machine becomes available. Between waiting for instruction by a physical therapist and the use of an exercise machine, the productivity and thus recovery of an individual is greatly diminished.
Although there currently exists a plurality of manually operated and motorized leg exercising devices that have been adapted as removable attachments to a wheelchair, the devices are often stationary, non-interchangeable with standard wheelchairs, structurally significant, and costly. Current leg exercising devices, in addition to having been adapted as removable attachments on a wheelchair, do not perform the basic function of a wheelchair leg rest. For example, U.S. Pat. No. 6,334,624 (Giglio) discloses a leg exerciser for the wheelchair bound including a frame which is placed on the floor. However, because the leg exerciser is structurally cumbersome and must be placed on the floor, the device is not portable.
In another example, U.S. Pat. No. 7,569,002 (Nativ) discloses a wheelchair provided with an exercise mechanism which allows a user to exercise his or her torso. In addition, the exercise mechanism also allows the user to exercise his or her legs either separately from or simultaneously with his or her torso muscle groups. However, the exercise mechanism as disclosed by Nativ is structurally integrated with the wheelchair and is thus non-interchangeable with a standard wheelchair.
In a further example, U.S. Pat. No. 8,469,866 (Hochberg et al.) discloses a wheelchair gym having a support bar releasably connected to the frame of the wheelchair, whereby leg supports for the patient's legs are attached to the opposite ends of the support bar. The leg supports may be moved up and down or may be splayed laterally. The leg supports each include an exteriorly housed hydraulic cylinder connected to the footrest. Within the hydraulic cylinder is a hydraulic piston that enables an individual to exercise his or her legs by moving each foot independently or simultaneously up and down on the leg supports in a walking or rowing manner. However, the wheelchair gym requires a support bar connected to the wheelchair of which the leg supports are subsequently connected to the wheelchair. Furthermore, because the resistance means including the hydraulic cylinder is housed on the outside of the leg supports, it can be damaged.
Lastly, U.S. Pat. No. 7,008,357 (Winkler), while not relating to a wheelchair, discloses a seat exercise device secured to a mobile platform (e.g., commercial aircraft, bus, train, automobile) for use by any passenger sitting onboard to reduce the risk of deep vein thrombosis during extended periods of travel. Although the seat exercising device includes a spring arranged between the leg support and the foot support such that a passenger may push down on the foot support to exercise his legs, the seat exercising device is not interchangeable or mountable on a wheelchair.
Therefore, there has been a long-felt need for a spring-loaded interchangeable wheelchair leg which allows a user to exercise lower extremities but still perform the same function as a typical wheelchair leg.